The present invention relates to reinforced hulls for a water craft, such as boats and air craft pontoons, and relates in particular to hulls of the above class having reinforced bottoms for protecting hulls against damage and possible loss of the craft, with which the hulls are associated, due to collision with floating debris, submerged objects or travel over snow, ice, growlers or mixtures thereof.
Most prior art hull structures are designed to meet this problem by providing "double bottoms" having various fixed configurations, such as bouyancy chambers filled with air or flotation and resilient materials sandwiched between bottoms to provide resistance to shock, as well as bouyancy.
Representative prior art structures are disclosed and described in U.S. Pat. Nos. 3,190,587, 3,680,516, 4,667,619 and 4,676,545.
The '619 patent shows a protective cover 7 fixed permanently to a hull 1.
The '545 patent is directed to a chassis structure including fore and aft cradles 10 and 11 connected to a floor tray 12 forming a bed for air, water and land craft of various configurations.
The '587 patent discloses a hull bottom overlay for a water craft which is inflatable to change the contour of the hull to provide stability, extra flotation or improved efficiency.
The '516 patent discloses a double bottom structure where a compressible, shock absorbing cushion is sandwiched between bottoms 2 and 10 and 11.
All of the above structures are fixed in that the extra hull elements are permanently attached.